A term time pro rata calculator works out your actual salary when you’re paid for a reduced number of weeks a year, rather than the standard 52. It applies two adjustments at once: one for your weekly hours compared with a full-time role, and one for the number of term weeks plus paid holiday you actually work. Most school support staff, from teaching assistants to office administrators, need this double calculation to know what they’ll really take home.
If you’ve ever tried to run your term-time salary through a normal pro rata calculator and ended up with a number that doesn’t match your payslip, you’re not alone. It’s one of the most common payroll confusions in UK schools, and it’s almost always down to the same mistake: treating a term-time role like an ordinary part-time job.
Why a Standard Pro Rata Calculator Gets Term-Time Pay Wrong
Our full pro rata salary calculator only does one job: it compares your weekly hours to a full-time week. Enter 20 hours against a 37.5-hour full-time role, and it tells you that you’re on roughly 0.53 FTE. Simple enough for an office worker who’s part-time all year round.
Term-time roles don’t work like that. You’re not just working fewer hours each week, you’re also working fewer weeks each year. A teaching assistant on 30 hours a week might be doing nearly full-time hours during term, but if they only work 38 or 39 weeks instead of 52, a huge chunk of the year isn’t being paid for at all, aside from statutory holiday.
That’s why term-time pay needs what payroll teams often call a “double pro rata” calculation, once for hours, once for weeks. Miss the second step, and you’ll overestimate your salary by thousands of pounds a year.
The Term Time Pro Rata Formula
Here’s the calculation a proper term time pro rata calculator runs behind the scenes:
Term-Time Salary = FTE Salary × (Your Hours ÷ Full-Time Hours) × (Term Weeks + Holiday Weeks) ÷ 52
Under the Working Time Regulations 1998, full-time UK workers are entitled to a minimum of 5.6 weeks’ paid annual leave, and this figure is added to your term weeks before the calculation is finished, because those holiday weeks are paid time even though you’re not in the building.
A typical English school year runs to roughly 39 term weeks, though this varies by local authority and by whether INSET (training) days are counted separately. Add the standard 5.6 weeks of holiday and you get a term-time fraction of around (39 + 5.6) ÷ 52 = 0.858. In practice, some councils calculate against 52.143 weeks rather than a flat 52, to account for the extra quarter-day the calendar picks up each year. It’s a small difference, usually under £100 a year, but it explains why two “correct” calculations can land on slightly different totals.
Key Inputs You’ll Need
Before you run any numbers, gather these four figures:
- Full-Time Equivalent (FTE) salary — the full annual pay for the role at 100% hours and 100% weeks. You’ll find this on the job advert, your offer letter, or the relevant pay scale.
- Your weekly hours versus the standard full-time week for the role (usually 36 to 37.5 hours for support staff, though teaching contracts often use 32.5 hours over 52.14 weeks).
- Term weeks worked — typically 38 or 39, but check whether INSET days sit inside or outside that figure.
- Holiday entitlement — the paid weeks built into your contract on top of term weeks.
Step-by-Step: How to Calculate Your Term-Time Salary
Working through it by hand makes the logic much clearer, even if you’ll use a calculator for the actual sums.
Step 1 — Find your FTE salary. Check the current NJC support staff pay scale or your local authority’s grading structure to confirm your spinal column point. For the 2025/26 pay year, entry-level support roles typically start somewhere around £22,000 to £23,500, rising through the scale from there.
Step 2 — Work out your hours ratio. Divide your contracted weekly hours by the full-time hours for the role. Someone on 30 hours against a 37.5-hour full-time week is working 0.8 of the hours.
Step 3 — Work out your weeks ratio. Add your term weeks to your statutory (or contractual) holiday weeks, then divide by 52 or 52.143 depending on your employer’s method.
Step 4 — Multiply everything together. FTE salary × hours ratio × weeks ratio gives you your actual annual gross salary.
Step 5 — Divide by 12 (usually). Most schools spread term-time pay evenly across all twelve months rather than paying only during term, so you receive the same amount whether it’s July or January.
Worked Example
Say Sarah is a teaching assistant on an FTE salary of £23,500. She works 30 hours a week against a full-time week of 37.5 hours, for 38 term weeks a year.
- Hours ratio: 30 ÷ 37.5 = 0.8
- Weeks ratio: (38 + 5.6) ÷ 52.143 = 0.8356
- Term-time salary: £23,500 × 0.8 × 0.8356 = £15,709 per year
Spread over 12 months, that’s about £1,309 a month before tax and National Insurance, paid consistently even through the summer holidays.
Term-Time Salary Examples at a Glance
| FTE Salary | Hours (of FT) | Term Weeks | Approx. Actual Salary |
| £22,000 | 37.5 of 37.5 | 39 | £18,850 |
| £23,500 | 30 of 37.5 | 39 | £16,130 |
| £23,500 | 25 of 37.5 | 39 | £13,440 |
| £26,000 | 32.5 of 37.5 | 38 | £18,830 |
| £20,500 | 20 of 36 | 38 | £8,880 |
These figures are indicative and will shift slightly depending on whether your employer uses 52 or 52.143 weeks, and how holiday entitlement is folded in.
Term-Time Contracts vs Ordinary Part-Time Contracts
It’s worth being clear-eyed about how different these two working patterns really are, because the payslip experience is quite different too.
| Feature | Term-Time Contract | Ordinary Part-Time Contract |
| Weeks worked per year | ~38–39 | Usually 52 |
| Calculation needed | Double pro rata (hours + weeks) | Single pro rata (hours only) |
| Pay during school holidays | Yes, spread across 12 months | N/A, works year-round |
| Common roles | Teaching assistants, admin, catering, caretakers | Retail, office, healthcare part-timers |
| Holiday pay handling | Built into the weeks calculation | Accrued separately, pro rata to days worked |
What Counts as a Term Week (and What Doesn’t)
This is where a lot of the confusion in staffrooms and payroll offices actually comes from. Term weeks usually refer to the weeks pupils are in school, but your contract might also count INSET days separately, on top of those weeks, since staff are required to attend even when pupils aren’t in. Some local authorities fold INSET into the 39-week figure; others add it as an extra week. If your total doesn’t match what you expected, this is the first thing to check with HR.
Local authorities aren’t fully standardised either. Some use 38 weeks, some 39, and a few use fractional weeks like 38.4 or 39.2 for extra precision. Scotland’s school calendar and term structure differs from England and Wales too, which is one reason a calculator built around a single fixed number of weeks will get things wrong for a meaningful share of readers.
Pro Rata Holiday Entitlement for Term-Time Staff
Under the Working Time Regulations 1998, every UK worker is entitled to a minimum of 5.6 weeks’ paid holiday a year, and this is always calculated pro rata for anyone working less than a full year or a full week. For term-time-only staff, this entitlement is typically already baked into the weeks figure used in the salary formula above, rather than being a separate pot of paid days off you request.
| Days Worked per Week | FTE Ratio | Statutory Holiday (Days/Year) |
| 5 (full-time) | 1.0 | 28 |
| 4 | 0.8 | 22.4 |
| 3 | 0.6 | 16.8 |
| 2.5 | 0.5 | 14 |
| 2 | 0.4 | 11.2 |
Following the 2022 Supreme Court ruling in Harpur Trust v Brazel, holiday pay for irregular-hours and term-time-only workers should be calculated using an average of actual pay received, rather than a flat 12.07% multiplier, which had previously been common practice in some schools. This shifted how a number of local authorities calculate entitlement, so it’s worth checking which method your employer currently applies. Acas has published detailed guidance on this for both employers and staff.
Common Mistakes That Throw Off the Numbers
Forgetting to add holiday weeks before dividing. Term-time pay is not simply term weeks × weekly rate. Skipping the 5.6-week addition is the single most common error people make when trying to check their pay by hand.
Using 52 instead of 52.143 weeks. There are just over 52 weeks in a calendar year once leap years are accounted for, and some payroll systems use the more precise 52.143 figure. It’s a small difference, but it can shift your annual figure by up to £100.
Mixing up teaching and support staff pay scales. Teachers sit on an entirely separate national pay framework from support staff, who are usually graded through their local authority’s NJC scale. Plugging teacher pay scale figures into a support-staff calculation (or vice versa) will produce a meaningless result.
Not clarifying whether INSET days are included. As mentioned above, this single detail can add or subtract a full week’s pay from your annual total, so it’s always worth confirming in writing.
Assuming pay stops in the holidays. It doesn’t, in the vast majority of cases. Term-time salaries are almost always spread evenly across 12 monthly payments specifically so staff have a predictable income through August and other school breaks.
Who Actually Needs This Calculation
Term-time pro rata calculations come up constantly for:
- Teaching assistants and higher-level teaching assistants (HLTAs)
- School administrators, receptionists and office managers
- Lunchtime supervisors and midday assistants
- Site staff, caretakers and cleaners on term-time contracts
- Catering and kitchen staff working school hours only
- Learning support and SEN assistants
- Anyone comparing a term-time job offer against a full-year role to see which actually pays better
If you’re weighing up two job offers, one term-time and one full-year, running both through the formula above (rather than just comparing headline FTE salaries) is the only way to see which one genuinely puts more money in your pocket. You’ll find more scenarios like this broken down in our full pay and salary guides.
A Note on Accuracy
Every one of these calculations depends entirely on the figures your employer gives you for term weeks, full-time hours and holiday entitlement — you can read about our calculators and how we keep these figures current each pay year. Two schools can advertise what looks like the same salary and hours but land on different actual pay simply because one uses 38 weeks and the other 39, or because one includes INSET days in that figure and the other doesn’t. If your own numbers don’t add up to what’s on your payslip, that’s a conversation for HR or payroll, not a sign the formula is wrong. According to Acas, employers should be able to give you a clear, written breakdown of how your term-time salary was calculated on request. For a broader look at pro rata pay outside of term-time roles, our complete UK pro rata salary guide covers standard part-time, annual leave and starter/leaver calculations in full.
Frequently Asked Questions
How is term-time only salary calculated?
It’s worked out using a double pro rata calculation: your weekly hours are compared to full-time hours, and your term weeks plus holiday entitlement are compared to a full 52-week year. Both fractions are multiplied against the full-time equivalent salary to give your actual annual pay.
Do term-time only workers get holiday pay?
Yes. Statutory holiday entitlement of 5.6 weeks is a legal minimum for all UK workers and is calculated pro rata for term-time staff. For most school support roles, this holiday pay is already included in the weeks figure used to work out your annual salary, rather than paid as a separate lump sum.
How many weeks is term time in UK schools?
Most English and Welsh schools run for 38 or 39 term weeks a year, though this varies by local authority and by whether INSET (training) days are counted inside or outside that figure. Scotland’s school calendar differs slightly again, so it’s always worth checking your own contract rather than assuming a standard figure.
Is term-time salary paid monthly or termly?
Almost always monthly. Even though you only work during term weeks, your annual salary is typically spread across 12 equal payments, so you receive the same amount in August as you do in October.
What’s the difference between a term time pro rata calculator and a standard pro rata calculator?
A standard pro rata salary calculator only adjusts for hours worked per week. A term time pro rata calculator adjusts for hours and for reduced working weeks, which is essential for anyone on a school-year contract rather than a year-round part-time role.